#include <stdio.h>
void main()
{
    int a,i,b,n;
    printf("There are following feiendly - numbers pair samller than 3000:\n");
    for(a=1;a<3000;a++)
    {
        for(b=0,i=1;i<=a/2;i++)
            if(!(a%i))
                b+=i;
        for(n=0,i=1;i<=b/2;i++)
            if(!(b%i))n+=i;
        if(n==a&a<b)
            printf(" %4d..%d ",a,b);
    }
    printf("\n");
}